Hi, we have a backyard pool in the Toronto area. We’re very exposed to the house behind us which sits on a higher grade. Along the back fence, we have pretty wet soil (if you dig down a couple of feet there is usually water pooling). We had planted mature cedars which unfortunately died – the landscaper did not use crushed rock or anything to prepare the bed. Also I now see from your site they should have removed the burlap from root balls and they did not. Can you recommend a specific evergreen that can survive these conditions and also provide guidance on the correct way to plant? Also, to avoid the wet soil issue – can cedars be planted in containers along that fence and survive the winter? We are looking for something that will grow quickly to give us privacy within a few years. Thanks!
Thanks for contacting Toronto Master Gardeners. It is challenging to keep evergreens alive in wet sites. Some evergreens that tolerate wet soil include balsam fir (Abies balsamea), black spruce (Picea mariana) and American holly (Ilex opaca) but these species grow into large trees. If you want a smaller hedge, a cedar cultivar may still be your best bet. The native eastern white cedar (Thuja occidentialis) in particular tolerates wet soil quite well but may not last long in an area that is constantly wet.
To increase the options of evergreens for your hedge you could plant evergreens in containers or create a berm for them. You will find options for evergreen hedges in this Toronto Master Guide: https://www.torontomastergardeners.ca/gardeningguides/evergreens-suitable-for-hedging-a-toronto-master-gardeners-guide/. If you decide to plant evergreens in containers, fill frost proof containers with good quality potting soil. Wood containers with drainage holes is a good option. Ideally the boxes should be 20 inches by 20 inches and 20 inches deep. You can line the sides of the boxes with sheets of Styrofoam which protects them from freeze thaw cycles during the winter. They need to be watered regularly up until the first frost with more frequent watering during hot spells. At the beginning of winter cover the top of the containers with mulch to protect the roots. Each spring top up the soil with organic material such as compost. For more information on potted evergreens please see: https://www.torontomastergardeners.ca/askagardener/container-planting/
A more expensive and labour intensive solution would be to build a berm. Berms are mounded hills of dirt constructed with fill such as plant debris, soil, sand or rubble and compost. Creating a berm where you want to plant the evergreens may improve the drainage for the their root systems. The berm can be supported by other plants and stones that will stop erosion. For more information on berms please see:
https://www.pennlive.com/gardening/2008/06/evergreens_for_wet_soil.html
You would need to consider the impact on water drainage on your property since the water from your neighbour’s property might be redirected. If you are considering this route it would be prudent to consult with a professional landscaper to establish whether this is an appropriate solution for this problem. You will find information about professional landscapers at this website: http://landscapeontario.com/find-a-company